do with；turn up；in charge of；now that；be hard on；look up；even if；go out；be supposed to；run after；argue with；complain about

21.Jack is so stubborn (顽固的) that it is useless trying to__________________him about it.

22．________________there are only ten minutes to go，why not set out at once?

23．When we entered the hall，all the lights______________suddenly.

24．The father____________________his children and permits them few privileges (特权)．

25．What will you______________the wallet you found in the library?

26．The nurse was left__________________the children.

27．You____________________________finish your homework on time.

28．To our surprise，he didn’t______________at his son’s wedding.

29．Don’t always______________the new words in a dictionary while reading.

30．The workers here often__________________their poor living conditions.